Moove over IPO: SAB Biotherapeutics to milk the stock market via SPAC

After grabbing government grants to develop its polyclonal antibody treatment for COVID-19, SAB Biotherapeutics is going public through a $118 million SPAC merger. The proceeds will bankroll a pipeline of treatments for various diseases that are produced by and extracted from genetically modified cows.

SAB is merging with Big Cypress Acquisition Corp., a special purpose acquisition company (SPAC) that went public in January before hunting for life sciences companies to acquire in the U.S. or Israel, according to a securities filing. 

Having screened more than 60 biotechs, the company landed on SAB and its “exciting approach to marrying the power of nature with advanced genomic technology exciting approach to marrying the power of nature with advanced genomic technology,” said Sam Reich, CEO of Big Cypress, in a statement.

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The new funds will bankroll the development of antibody treatments for immune system disorders, cancer and infectious disease, as well as the cow-based technology that underpins them. The deal is slated to close in the fourth quarter of this year. 

Using polyclonal antibodies to treat disease is not a new idea. Made from donor plasma, these treatments contain many different antibodies and are used to treat primary immune disorders, prevent rejection in organ transplant and most recently, COVID-19. 

SAB’s approach is a little different and involves giving a herd of genetically modified cows a target antigen, triggering the production of fully human antibodies. The company then collects plasma from the animals and isolates the antibodies, resulting in an antibody medicine. 

The company picked cows because they have a more powerful immune response than humans and, being large animals, can produce a lot more antibodies than human donors can. Another challenge with human donors is that their plasma contains antibodies against multiple kinds of pathogens and not necessarily the pathogen a company is targeting. 

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GigaGen—now part of Grifols—is tackling these problems a different way. Rather than produce antibodies in animals, it uses single-cell sequencing to “capture and recreate” whole libraries of antibodies from different people, such as patients who have recovered from COVID-19. From those libraries, the company can choose which of those antibodies to turn into recombinant polyclonal antibody treatments.

SAB’s lead program is a treatment for COVID-19, which is funded by grants from the Biomedical Advanced Research and Development Authority and the Department of Defense. It is also working on a treatment for seasonal flu, cancer, Type 1 diabetes and organ transplant rejection.